The invention relates to processes for the polymerization of 1,3-cyclodienes with vinylaromatic hydrocarbon compounds and to the copolymers produced therefrom.
Some copolymers of 1,3-cyclodienes with vinylaromatic hydrocarbons such as 1,3-cyclohexadiene and styrene have been disclosed in recent years. While this basic copolymer, that is, the copolymer formed by polymerizing styrene with 1,3-cyclohexadiene employing a monofunctional organolithium initiator, has been previously disclosed, little has been known about the product or the process and the effect various parameters have on the reaction. It has now been discovered that higher conversions than heretofore possible can be achieved by choosing a particular diluent for the reaction mixture. Further, a 1,3-cyclodiene/vinylaromatic copolymer having higher tensile strength than heretofore possible has been discovered.
It is an object of the invention to provide an improved method for the polymerization of 1,3-cyclodienes and vinylaromatic hydrocarbons. Another object of the invention is to provide a method to improve the polymerization rate and the percent of conversion to copolymer. Still another object of the invention is to provide a 1,3-cyclodiene/vinylaromatic hydrocarbon copolymer. Other objects, aspects and advantages of this invention will be apparent to one skilled in the art upon studying the specification and the appended claims.